Breastfeeding optimally supports the development of the infant and protects against infections. However, not all infants are in the position to receive human milk. It is therefore a continuing aim to provide infant formula, which simulates the functions of human milk. In addition to the desired compositional similarity between infant formula and human milk, it is also particularly desirable to mimic the protective effects of human milk. Human milk has for example been shown that human milk protects against infections and allergies.
In current infant formulas, the casein to whey ratio resembles that of human milk as closely as possible. It is believed that this ratio results in optimal growth for the infant. However, there are still several downsides attached to the use of bovine, whey dominant protein sources. These whey dominant formulas do not optimally protect against infections. Administration of such formula results in an impaired development of the intestinal flora of the infant compared infants fed with human milk, particularly in the first three to four weeks of life. The flora of infants fed with the whey dominant formula contains more or less the same bacterial genera as the human milk fed infants, however, the quantity of beneficial bacteria is reduced in infants receiving the whey dominant formula compared to infants receiving human milk. Moreover, the flora of infants fed with formulas containing whey dominant bovine protein source contain increased amounts pathological bacteria such as clostridia and enterobacteria. Hence, feeding an infant with whey dominant formula results in the formation of a “suboptimal intestinal flora”.
As the very young infants have an immature immune system and an immature intestinal tract, development of the suboptimal intestinal flora may result in infection, diarrhea, allergy and inflammation. Especially infants with the age between 0 and 30 days and fed with bovine whey-dominant protein containing formula suffer from these risk as their faecal flora is most different from those infant fed human milk.